"The new machine is called Tianhe-2 and it's actually at the National Defense University in China," says Thom Mason, director of Oak Ridge.

Titan's slip from the top spot is not unusual: Nations regularly swap the No. 1 slot. But because of a series of automatic spending cuts locked into the Federal government's budget, Mason is afraid America may soon slip permanently behind.

"The issue is not so much who's No. 1 in the horse race," he says. "But we think it's important for the U.S. to always be amongst that group that is pushing the envelope."

The automatic cuts were never supposed to happen. Back in 2011, Congress passed them as a threat: If government spending wasn't brought under control by 2013 through tax increases or a more tailored set of cutbacks, these general, across-the-board cuts would go into effect. Democrats and Republicans could never reach a deal. So this spring, the cuts came in.

Everyone from preschool teachers to fighter pilots had to tighten their belts. Oak Ridge saw its budget slashed by about 7 percent in 2013 — that's nearly $100 million.

But while the lab's budget is down, its electric bill isn't. All told, Oak Ridge's machines suck up as much juice as a small town, 25 megawatts: "For every megawatt of power we use a year, it costs us about a million dollars, and that's real, cold hard cash," says Jeff Nichols, the lab's associate director for computing.

Nichols says that the lab changed pension plans and reduced benefits to make up for some of the cuts. But money will also have to come from plans for the future. Researchers had hoped to replace Titan with another superfast machine in 2017.

"As we look at the budget scenarios we're facing, that next machine is moving further and further out into the future," Mason says.

The automatic cuts are also hurting the researchers who use Titan, like Sally Ellingson, a graduate student at the University of Tennessee. She's currently teaching Titan to screen chemical compounds that could be used as drugs to treat diseases. "Recently I ran a job where I tested over 4 million compounds in just a couple hours," she says.

Ellingson is set to graduate next year, and she's already writing a grant that will allow her to continue her research.

But grant agencies like the National Institutes of Health have suffered budget cuts too. NIH says that it is funding hundreds fewer proposals than in previous years. And the approval rate for grant applications submitted to NIH was already down to 18 percent from around 30 percent in 2000, even before the automatic cuts. The National Science Foundation, another major funder, says it's only funding roughly 1 in 5 of the proposals it receives.

"It's very, very tough when you're young to get any funding at all for what you're doing. Even if you're very brilliant, such as Sally [Ellingson]," saysJeremy Smith, the head of Ellingson's supercomputing group. He sits on peer-review panels that approve government grants. These days, he says, the panels get way more proposals than they can fund.

"At least two or three of those proposals that get rejected are fantastic science," Smith says.

He says he's worried that the climate could force Ellingson out of research. "She'll have no problem getting a job, but the risk has increased now that [the job she gets] will not be inventing the new medicines and products that will drive the economy in the future," Smith says.

For now, it seems like the cuts are here to stay. To stop the automatic budget declines, Congress would have to find ways to cut the deficit, either through different cuts or by the introduction of new taxes, or both. Against the backdrop of mammoth, trillion-dollar budget battles, science is likely to get lost, warns lab director Mason. "It's easy to miss something that's a pretty small part of the federal budget," he says.

Before the government shutdown and the debt ceiling debate earlier this month, there was sequestration. Remember that - the automatic spending cuts the government imposed back in March? Well, all kinds of agencies now feel the sting of those cuts including the scientists who rely on the country's most powerful computer.

NPR's Geoff Brumfiel reports.

(SOUNDBITE OF MACHINERY)

GEOFF BRUMFIEL, BYLINE: At the government's Oak Ridge Laboratory in Tennessee is a powerful supercomputer. It's called, Titan. To the untrained eye, it looks like rows of black cabinets set down on a pristine white floor but inside are hundreds of thousands of microprocessors.

JEFF NICHOLS: This is like what you what you would have in your office, for example. It just so happens that you have rows and rows of cabinets of these kinds of systems.

BRUMFIEL: Jeff Nichols is the lab's associate director for computing. All these processors working together can simulate everything from global climate to the core of a nuclear reactor but doing so requires a lot of electricity. All-in-all Oak Ridge's machines suck up as much juice as a small town, 25 megawatts.

NICHOLS: For every megawatt of power we use, for a year, it costs us about a million dollars. And so, that's cold hard cash.

BRUMFIEL: That power bill comes in regardless of the lab's budget, which is bad news this year, because the budget is down nearly $100 million, seven percent.

NICHOLS: We had to reduce our benefits. We had to change our pension plans. We had to do all the kinds of things like that in order to reduce our overall costs.

BRUMFIEL: The cause is a series of automatic budget cuts that kicked in earlier this year. The cuts are designed to keep government spending down and everyone from preschool teachers to fighter pilots have had to tighten their belts. Congress didn't do anything about the cuts when it ended the recent government shutdown and without action they could grow even deeper in 2014. That is creating a big problem at the lab because Titan will soon need to be replaced with a new machine.

THOM MASON: As we look at the budget scenarios we're facing, that next machine is moving further and further out into the future.

BRUMFIEL: Thom Mason is director of Oak Ridge. Turns out, supercomputers are a lot like regular computers, they go out of date in a hurry. When NPR first visited Titan a year ago, it was the world's fastest. Now, it's the world's second fastest.

MASON: The New Machine is called Tianhe-2. And it's actually at the National Defense University in China.

BRUMFIEL: The automatic cuts are also hurting the researchers who use Titan, like Sally Ellingson. Sally is a graduate student at the University of Tennessee, who fell in love with the Oak Ridge computers at first sight.

SALLY ELLINGSON: I'm sort of a nerd like that, just...

(LAUGHTER)

ELLINGSON: Just the thought of it fired me up. I mean, just the possibilities - the endless possibilities of things you could do with it.

BRUMFIEL: Now she's teaching Titan to screen chemical compounds that could be used as drugs to treat diseases.

ELLINGSON: Recently, I ran a job where I tested over four million compounds in just a couple hours.

BRUMFIEL: In other words, Titan can do in hours what it would take years to do in the lab. She's set to graduate next year, and she's already working on a grant that will allow her to continue her research. But grant agencies like the National Institutes of Health, they're cut, too. NIH is giving out hundreds fewer grants this year.

ELLINGSON: Yeah. Certainly, I hear from other people that funding is hard right now. And I'm just now learning the ropes and it's my first big proposal that I'm writing.

JEREMY SMITH: It's very, very tough when you're young to get any funding at all for what you're doing, even if you're very brilliant, such as Sally.

BRUMFIEL: Jeremy Smith is the head Sally's super computing group. He sits on peer-review panels that approve government grants. These days, he says, they get way more proposals that they can fund.

SMITH: At least two or three of those proposals that will be rejected are fantastic science.

BRUMFIEL: Smith says he's worried that the climate could force Sally out of research.

SMITH: She'll have no problem getting a job. But the risk has increased now that this will not be inventing the new medicines and products that will drive the economy in the future.

BRUMFIEL: The same could be said for young researchers using Titan to study everything from earthquakes to biofuels. And as these automatic cuts drag on, researchers across the sciences have similar fears. Without money for new ideas like Sally's, and new machines like Titan, they say America will start slipping further and further behind.